The filling of containers with liquids, such as dairy products, today places high demands on a hygienic environment. Aseptic conditions are required when the products contain bacteria which could multiply and become a health hazard.
The currently used methods for filling containers with liquids are based on the liquid being stored in a main tank. In order to transfer the correct amount of liquid to each container, the liquid is first transferred from the main tank to a number of separate balance tanks. Then the liquid is transferred from the balance tank to a container. In the balance tank, especially in corners and along edges where the liquid is stagnant, and in connections to and from the tank, bacteria in the liquid tend to grow and multiply, which in turn may cause cultures injurious to health. This means that it is necessary to continuously clean a large number of balance tanks to retain an aseptic environment and to avoid health hazards caused by bacteria in the final product, for instance in milk.
The balance tanks are in many cases equipped with some sort of level monitor which monitors that the correct amount of liquid is transferred from the main tank. The liquid is transferred between the tanks through conduits and the flow is controlled by means of valves, in which bacteria cultures can also grow.